How do I create a squeeze tube packaging?
In this case I would not go with Curves as they aren't best choice in terms of modeling in Blender. My method is based upon simple plane which gives us very simple base geometry and allows to have nice top part of model. Starting with circle will give massive headache to close and straighten up this part of a mesh.

This is method I've used to model it:


Add a Plane - Shift + A > Mesh > Plane.
Go to Edit Mode.
Select all vertices, press E and extrude along Z axis.
Select top edge and press S > Y to squize it.
Extrude top edge along Z axis once more. 


You should have now something like this:




Add Modifier > Subdivision surface and set it to 4-5 (preview and render).


Now we need to crease some edges.


Select all top vertices and set Mean Crease to about 0.6.





Do the same with bottom vertices but this time Mean Crease should be 0.3.
Add Loop Cut (CTRL + R then hover cursor over mesh) to 'main part' of the mesh and place it near bottom edge.
Choose Smooth Shading. Object Mode > Tools Panel (left side of the screen) > Shading > Smooth.




Here is blend file to play with: